1. Field of the Invention
The present invention relates to ground anchors, and more particularly to deadman anchors able to secure modular buildings subject to earthquake, high winds, and floods.
2. Description of Related Art
Natural disasters such as floods and earthquakes cause far more damage than is necessary when equipment, fixtures, and buildings come loose and are allowed to knock about. Floods in particular are able to float propane tanks off their foundations and carry them away. Such floating tanks can easily collide with other debris and explode. Mobile homes that would otherwise suffer relatively minor damage can be completely destroyed if they are bounced off their foundations or support jacks during an earthquake.
Of course many anchoring methods and devices exist that could be used in these and similar situations. But the prior art anchoring methods and devices available are usually expensive and/or not all that satisfactory.
Soil anchors are well-known. Some need to have a hole excavated and the anchor buried in the hole. Others screw themselves into the ground and are expected to resist being pulled out. Tents of all sizes have been anchored by tethers that are tied off to spikes driven into the ground. Such spikes are best driven in at right angles to the expected load so that they don""t pull out so easily.
However, when extreme forces are applied to prior art soil anchors, they pull out because the installation loosened the soil they""re embedded in, and/or too little lateral area in the soil is being loaded.
Boyce Cockman describes a screw-in type post anchor in U.S. Pat. No. 4,923,165, issued May 8, 1990. He admits that a problem occurs in loosening the soil in which the anchor is expected to grip. So the solution proposed is to squeeze the soil in a vice arrangement after the anchor is in place. The problem with trying to recompact the disturbed soil this way is the plug of recompacted soil forms a cylinder that is not well anchored to the undisturbed soil surrounding the anchor.
A drive anchor with retaining flukes was described by M. A. Jackson, in U.S. Pat. No. 3,302,347, issued Feb. 7, 1967. A power hammer is used to drive a ground anchor into place. A metal shaft with a pointed end has flukes welded to it to form what looks like an arrowhead. A tailpiece of each fluke is not welded to the shaft behind a radial bend-groove. The fluke tailpieces bend on the bending groove and flip out when the drive anchor is forcibly rotated or tugged. The bent pieces thereafter lock the drive anchor in essentially undisturbed compacted earth. However, a large amount of force is usually needed to get the bending grooves to fold, and the folded metal is thus weakened and exposed to rust.
An object of the present invention is to provide a soil anchor that is effective and useful where extreme tensile loading will occur.
Another object of the present invention is to provide a soil anchor that is simple and easy to insert into the ground and that does not loosen the naturally compacted soil it needs to anchor within.
Briefly, a deadman anchor embodiment of the present invention comprises a heavy steel rod with several inches of machine threading at a back end, and an arrowhead with a pair of wedge-shaped wings at a front end. The wedge-shaped wings are welded to the steel rod. A pivotable fluke is hinged to the shaft with a lateral pin. The whole unit is driven into the soil with a pneumatic jack-hammer until the threads at the back end are almost completely buried. A stabilizer vane and interlocking cap are then placed over the end flat on the ground. Nuts are put over the threaded end and tightened so that the whole unit is drawn back out a few inches. The fluke folds out perpendicular to the shaft and locks compacted soil between it and the cap. The stabilizing vane braces the top end of the anchor against lateral forces.
An advantage of the present invention is that a soil anchor is provided that is effective and useful where extreme tensile loading will occur.
Another advantage of the present invention is that a soil anchor is provided that is simple and easy to insert into the ground and that does not loosen the naturally compacted soil it needs to anchor within.
The above and still further objects, features, and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings.